Refrigerator cabinet and evaporator structure



Dec. H, 1956 J. w. JACOBS ETAL REFRIGERATOR CABINET AND EVAPORATOR STRUCTURE 2 Sheets-Sheet 1 Filed July 8, 1953 II I I illkalil INVENTOR.

W. Jacobs and H. Wurfz James y Clifford IP11? fialnt u,

Their Attorney.

Dec. 11, 1956 J. w. JACOBS ET AL 2,773,361

REFRIGERATOR CABINET AND EVAPORATOR STRUCTURE Filed July a, 1955 2 Sheets-Sheet 2 INVENTOR.

James W. Jacobs and Clifford H. Wurfz BY Their Attorney.

United States Patent REFRIGERATOR CABINET AND EVAPORATOR STRUCTURE James W. Jacobs and Clifiord H. Wurtz, Dayton, Ohio, assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application July 8, 1953, Serial No. 366,692

3 Claims. (Cl. 62-1173) This invention relates to refrigeration and particularly to refrigerators of the domestic or home freezer type.

At present there are a great number of vertically elongated home freezer cabinets in use employed to quickly freeze food products and to store pre-frozen foods therein. The main food storage chamber of such a cabinet is usually divided by food supporting shelves into a plurality of vertically superimposed compartments. This presents the problem of maintaining the same temperature differential between the superimposed compartments from the top to the bottom of the main chamber so as to prevent warm pockets in portions of the chamber. Freezer cabinets of this type and having a refrigerating system associated there with including refrigerant evaporating portions or conduits so segregated and remotely arranged relative to one another, to overcome the problem just set forth, requires a large number of conduit joints or connections which are tedious to make and which increase the manufacturing cost of the refrigerators. We have, after considerable development, experimental and test work, discovered how a uniform, temperature in a plurality of superimposed compartments from the top to the bottom of a vertically elongated home freezer cabinet can be maintained. We have also discovered that this uniform temperature can be obtained by a novel arrangement of refrigerant evaporating portions of a refrigerating system associated with the refrigerator cabinet which will greatly reduce the number of tedious and expensive conduit joints or connections to be made.

An object of our invention is to provide an improved and less expensive home freezer or frozen food storage refrigerator of the vertically elongated front opening type.

Another object of our invention is to provide a novel arrangement of elements forming compartments within a vertically elongated freezer or frozen food storage chamber whereby to provide conduction of heat from certain walls of compartments in the main storage chamber to certain other walls thereof so as to reduce to a minimum the temperature differential between upper and lower compartments in the chamber.

A further object of our invention is to arrange refrigerant evapora-tors and/or refrigerant evaporating passages or conduits of a refrigerating system associated with a vertical home freezer and frozen food storage cabinet in such a manner as to obtain a balanced cooling effect throughout the main chamber of the cabinet and between compartments therein with a minimum of scaled conduit joints or connections.

In carrying out the foregoing objects it is a still further and more specific object of our invention to secure a plurality of substantially U-shaped sheet metal members or structures to one another in such a manner that one structure will cooperate with another to form wall continuations thereof and other walls providing compartment forming partitions in a main chamber of a vertically elongated home freezer cabinet.

With these and other objects in view, the present inven- "ice ous parts of our apparatus and in the cooperation therebetween whereby the objects contemplated are attained, as hereinafter more fully set forth, defined in the claims and illustrated in the accompanying drawings, wherein:

Figure 1 is a front view of a vertical home freezer cabinet having our invention embodied. therein and showing the door providing access to the food storage chamber thereof in open position;

Figure 2 is a combined perspective view of the inner structural arrangement of the refrigerator cabinet shown in Figure 1 and diagrammatically shows a closed refrigerating system associated with the cabinet;

Figure 3 is a plan view of one of the sheet metal evaporators employed in our freezer cabinet before being bent into its U-shape form as shown in Figure 2;

Figure 4 is a plan of another sheet metal evaporator employed in our freezer cabinet before being bent into its U-shape form as shown in Figure 2;

Figure 5 is an enlarged sectional view taken on the line 5-5 of Figure 2 showing the mode of attaching the bight portion of one of the U-shaped sheet metal evaporators to a side wall of a U-shaped liner;

Figure 6 is an enlarged sectional view taken on the line 6-6 of Figure 2 showing the mode of securing an arm of a U-shaped sheet metal evaporator to the top edge portion of a metallic liner;

Figure 7 is an enlarged sectional view taken on the line 7-7 of Figure 2 showing the mode of attaching a pan member to the bottom edge portions of the U-shaped metallic liner; and

Figure 8 is an enlarged fragmentary sectional view taken on the line 8--8 of Figure 3 showing refrigerant passages formed in a sheet metal evaporator.

The refrigerator illustrated in the drawings is of the vertically elongated, rectilinear, front opening domestic or home freezer and frozen food storage type. In the construction shown in Figure 1, the refrigerator cabinet 10 has an exterior shell 11, forming an outer housing for the cabinet, and an inner liner structure forming a main food storage chamber 12 within cabinet 10. This inner liner structure will be described in detail hereinafter. Walls of chamber 12 or of the liner structure are spaced from the outer cabinet housing 11 with the space therebetween substantially filled with suitable insulating material 13 as is common practice in present day construction of refrigerator cabinets. The food storage chamber 12 is open at its forward side to afford access to the interior thereof. A door 14, hingedly mounted upon cabinet 10, is associated with the chamber access opening and normally closes the same. Outer cabinet shell or housing 11 extends below the bottom of food storage chamber 12 to provide a mechanism or machine compartment in the lower portion of the refrigerator cabinet 10 normally closed by a cover 15.

A closed refrigerating system associated with cabinet 10 comprises in addition to refrigerant evaporators, refrigerant evaporating conduits and/ or passages, to be hereinafter more fully described, means for supplying or directing refrigerant therethrough in a prescribed manner. This means constitutes a refrigerant translating device and is in the form of a motor-compressor unit 16 (see Figure 2) having a conduit connection 17 with a condenser 18. A capillary tube or the like 19 connected to condenser 18 serves as a means for conveying refrigerant compressor of the motor-compressor unit 16. A sub stantial portion of the length of tube 19. is preferably secured in intimate thermal contact with the gaseous refrigerant return conduit 21 so as to form a heat exchanger therebetween for purposes now well known to those skilled in the art. An electric circuit and a thermostatic control therefore is provided to energize and deenergize the electric motor of unit 16 of'the refrigerant translating device. Operation of unit 16 is controlled by a suitable or conventional thermostatically operated snap acting switch 23. This switch has a thermal power unit such as a bulb 24, tube 26 and bellows 27 associated therewith. A volatile fluid is sealed in the power unit of switch 23 for causing the bellows to expand and/or contract to actuate the snap acting mechanism of the switch. Electric switch 23 opens and closes a set of contacts 28 and 29 therein, connected to the electric power lines '31 and 32 leading to unit 16, for starting and/or stopping operation of the motor and consequently the compressor of unit 16. While we have shown the thermal bulb 2.4 as being secured in intimate thermal contact with the refrigerant return flow conduit 21 it is to be understood that this bulb can be attached to any portion'of the refrigerating apparatus as may be desired.

According to our invention it is desired to construct the inner liner structure of cabinet '10, which forms the main food storage chamber 12 thereof, in a low cost manner and to arrange the refrigerant evaporators or-evaporatmg conduits or passages in such a way that effective and elficient cooling of chamber '12 will be obtained.

The inner structure of cabinet includes a substantially U shaped metallic liner upturned to form three walls of the vertically elongated main chamber 12 within cabinet 10 (see Figure 2). In other words the -U-shaped 'llIlCI forms the upright back-and two opposed sidewalls 36, 37 and 38 respectively of chamber 12. The liner is open at 1ts upper and lower ends and we close the lower open end thereof with a metal pan-like member 39 which is secured to the bottom edge portions of the liner by a plurality of rivets 40 (see Figure 7). The open upper end of the liner within cabinet 10 of the present disclosure is closed by an arm of a substantially U-shaped sheet metal evaporator as will be hereinafter described. The 'U-shaped sheet metal evaporators employed in the construction of our home freezer cabinet, as shown in Figure '2 of the drawings, may be formed by superimposing an embossed sheet of metal upon another flat sheet of metal and brazing or welding the sheets together whereby the embossations in the one sheet provide refrigerant evaporating passages therealong. Such a brazed structure is then bent .to provide a substantially U-shaped sheet metal evaporator having arms and a bight portion intermediate and connecting the arms. However we prefer to use U-shaped refrigerant evaporators constructed bya more modernand practical method such as is disclosed in the patent to George R. Long, No. 2,662,273, issued December 15, l953,-entitled Methodof Making Heat Exchanger Structures, and assigned to the assignee of the present application. This newer manner of makmg sheet metal evaporators is commonly referred to as aroll=forged welding or bonding method as distinguished froma'pressediforge weld.

Referringnow'to Figure 3 of the drawings we show one of the sheet metal evaporators employed inthe present home freezer cabinet in flat plate form prior to being bent along the dot-dash lines indicated at AA and BB into'lthe U-shaped-form thereof shown in Figure 2. This evaporator is provided with an upturned edge portion 41 "along one iof its endsand a downturned edge portion 42 along the opposite end to'form flanges which areutilized to receive rivets for securing the evaporator to the U- shaped metallic liner. This evaporator is further provided with a refrigerant inlet opening 43 at one edge of the plate -'which connects with refrigerant expansion or evaporatirig passages formed in the plate. These refrigerant evaporating passages include a straight "run "44 extending from the'inlet opening43 to a'point adjacent to and along the other end of the plate.

tioned evaporator is secured thereto.

food supports therein.

Passage 44 is in communication with a plurality of passages 46 at one side of the line AA or to the left thereof as viewed in Figure 3. A series passage 47, located intermediate the lines AA and BB, is in communication at one end thereof with a passage 46 and communicates at the one end thereof with passages 48 at the other side of line BB or .to the right thereof as viewed in Figure 3. A passage 49 communicates with one of the passages 43 and extends to an outlet opening 51 at the one edge of the plate adjacent inlet opening 43. The end portion of the plate to the right of line BB as shown in Figure 3 is bent downwardly along the line BB and the end portion of this plate to the left of line AA is also bent downwardly along the line A--A. This forms a substantially U- shaped sheet metal evaporator having arms 53 and 54 and a bight portion 56 intermediate the arms (see Figure 2). The U-shaped sheet metal evaporator thus formed is rotated and placed within the U-shaped liner so as -to dispose the one arm 53 flush with the upper edge of the U-s'haped liner, to locate the bight portion 56 adjacent side wall 37 of the liner and to dispose arm 54 below and in spaced relation to arm 53 for providing a horizontal packaged food support within chamber 12. The vU- shaped sheet metal evaporator thus positioned is then secured to the U-shaped liner by suitable rivets 57 along the flanges 41 and 42 and at the bight portion 56 thereof so that arm 53 of the evaporator forms a eontinuationof the liner to provide the top wall of main food storage chamber 12.

Referring to Figure 4 of the drawings we show another sheet metal evaporator employed in the construction of the present home freezer refrigerator in substantiallyfiat plate form prior to being bent along the dot-dash lines indicated at CC and D-D into the U-shaped form thereof-shown in Figure 2. Another or second evaporator is provided with an upturned edge portion 53 along .one of itsends and a downturned edge portion 59 along its opposite end to form flanges which are utilized to receive rivets for securing this evaporator to the .U-shaped metal liner in substantially the same manner that the firstmen- This another .or second evaporator is further provided with a refrigerant inlet opening 61, located between the dot-dash lines CC and DD, which connects with refrigerant expansionor evaporating passages formed in the plate. These .pas-

sages include a run 62 leading from the inlet opening 61 across the line DD and communicating with a plurality of passages 63.at one side of line DD or to the right thereof as viewed in Figure 4. Apassage-64 at one end of the .plate evaporator communicates with one of the passages .63 and extends entirely along the plate,,across lines DD and .C-C,ft0 the other end thereof where it communicates with one of a plurality of passages 66 on one I .side. of. line C.C or to the left'thereof. as viewed in Figure 4. .A passage 67 communicates with one of the'passages 66 and with a waflie-like accumulator6811ocatedbetween .the lines C-C and DD. Another passage .69 communicates with the .waffie-like .accumulator68 and leads 'to'an outlet opening71 provided in the plate in thevicinity of line .C-C. The end portion of the plate totheright -'of -linefD-D as shown in Figure 4 is bent downwardly .along.the.line DD. and the end .portionof the'plate' to thelleft ofthejline CC isalso bentdownwardlyalong the line CC. This forms a substantially Urshaped sheet metalevaporator having arms 72 and 73 -,and a bight portion -7.4-intermediate these arms (see Figurel). This second U-shaped sheet metal evaporator is rotated and placed within the U-shaped liner intermediate thefirst mentioned or uppermost evaporator and the chamber bottom wall 39. so as to dispose thebight portion74 adjacent the side wall38 of the liner. The spaced apart arms 72 and 73 of the lower U-shaped evaporator form refrigerated partitions within chamber12 and provide packaged The flanges58"and"59 at'the end liner bysuitable rivets in a manner similar to the securement ofthe first mentioned or upper U-shaped sheet metal evaporator thereto.

The inlet opening 43 and the outlet opening 51 at the edge ends of the upper U-shaped sheet metal evaporator are suitably dilated, as described in the copending application heretofore referred to, for receiving the end of conduit 19 and the end of a conduit 77. The inlet 61 and outlet 71, at a cut out edge or slit portion, in the lower U-shaped sheet metal evaporator is also dilated for receiving the ends of conduits77 and 21 respectively. Conduit or tube 19 is bonded or sealed to the refrigerant inlet opening 43 of the upper sheet. metal evaporator in any suitable or conventional manner. The conduit 77 forms another refrigerant evaporatingconduit and has its one end bonded or sealed to the outlet opening 51 of the upper evaporator and has its other or lower end 78 bonded or sealed to the inlet opening 61 of the lower evaporator. A portion of conduit 77, intermediate the ends thereof, is formed into a flat oil as at 79 and this coil is secured in intimate thermal contact with the outer surface of side wall 38 of the U-shaped metallic liner by suitable clamps 81 and screws 82 so as to extend over and along a substantial portion of the side of the upper compartment provided in chamber 12 by the first or uppermost Ushaped evaporator. The one or upper end of conduit 21 is bonded or sealed to the outlet opening 71 of the second or lower sheet metal evaporator. Side wall 38 of the U- shaped liner is slit or cut away (not shown) at the point where the end 78 of conduit 77 and the end of conduit 21 projects through the liner and is joined to inlet opening 61 and outlet opening 71 respectively. This portion of side wall 38 of the U-shaped liner is shown broken away in Figure 2 of the drawings to more clearly illustrate the vertical disposition of the wafile-like refrigerant accumulator 68 of the lower sheet metal evaporator within the liner.

Since the food compartment formed by the uppermost U-shaped evaporator in the top portion of chamber 12 is usually more difficult to cool than the lower compartment or lower portions of chamber 12 it is effectively cooled in the present arrangement by concentrating refrigeration thereto in a specific manner. Also in order to accomplish the objects of the present invention of utilizing low cost substantially U-shaped sheet metal evaporators for coop eration with a substantially U-shaped metallic liner to form a continuation of this liner and provide the top wall of food storage chamber 12 within cabinet a special refrigerant evaporating circuit is provided which reduces to a minimum the number of brazed or otherwise sealed conduit joints or connections to be made for the circuit. When switch 23 closes contacts 28 and 29 electric current is caused to flow by way of wires 31 and 32 through the motor of unit 16 to operate the same for driving the compressor within this unit. Operation of the compressor draws vaporized refrigerant therein, by way of conduit 21, from the waffle-like accumulator 68 in the lower U- shaped evaporator. The compressor compresses this refrigerant gas and forwards the compressed refrigerant to the condenser 18 by way of conduit 17. Condenser 18 may be cooled in any suitable or desirable manner so as to liquefy the compressed refrigerant entering the same. Liquid refrigerant is directed, by the capillary tube 19, from condenser 18 into the inlet 43 of the upper U- shaped sheet metal evaporator. This refrigerant flows through passage 44 horizontally across the top arm 53 and downwardly across the bight portion 56 into the plurality of parallelly communicating passages 46 in the upper U- shaped evaporator. Thus this first stage of refrigerant expansion or evaporation is somewhat concentrated in the lower arm 54 of the upper evaporator. The refrigerant then flows into the passage 47 in the bight portion 56 of the upper evaporator. Passage 47 directs the refrigerant into the plurality of parallelly communicating passages .48 in the upper arm 53 to thereby also concentrate evaporation of refrigerant therein or in the top wall of chamber 12 formed by the evaporator arm 53. Passage 49 conveys the refrigerant from passage 48 to the outlet 51 of the upper U-shaped sheet metal evaporator. Refrigerant leaving the upper evaporator by way of conduit 77 located outside chamber 12, flows in coil 79 back and forth along the one side wall 38 of chamber 12 formed by the U-shaped metal liner. The end 78 of conduit 77 directs refrigerant from coil 79 to the inlet 61 of the lower U-shaped sheet metal evaporator whereupon it flows, by way of passage 62, into the plurality of parallelly connected passages 63 in the bottom arm 73 of this second or lower evaporator. Due to the fact that cold air in chamber 12 tends to fall toward the bottom thereof this concentration of evaporating refrigerant in passages 63 of arm 72 in the lower evaporator is ample to cool the compartment intermediate this evaporator and the bottom wall or pan member 39 to a temperature far below 32 F. without necessity of refrigerating other walls of this lower compartment. Refrigerant leaving the passages 63, by way. of passage 64, flows into the plurality of parallelly communicating passages 66 in the upper arm 72 of the lower U-shaped sheet metal evaporator. The passage 67 directs refrigerant from the passages 66 into the vertically disposed waffie-like refrigerant accumulator 68. Accumulator 68 insures complete evaporation or vaporization of refrigerant in the low pressure side of the refrigerating system to thus prevent the flow of liquid refrigerant back to the compressor. Gaseous refrigerant flows out of accumulator 68 to the outlet 71 of the lower sheet metal evaporator by way of passage 69. Conduit 21, connected to the refrigerant outlet 71, thence conveys gaseous refrigerant back to the compressor of unit 16. Thus refrigerant is directed from the refrigerant translating device, partly in series and partly in parallelly communicating passages, through and across various walls of the U-shaped sheet metal evaporators and/ or across a plurality of walls of chamber 12 with a minimum of conduit joints. In fact the assembly of the refrigerating apparatus described and the connection of the refrigerant translating device to refrigerant evaporating portions of the closed refrigerating system associated therewith is accomplished by the making of only four brazed or otherwise suitably sealed joints. These four joints include sealing of conduit 19 to inlet opening 43, of the upper u-shaped sheet metal evaporator, sealing of conduit 77 to outlet opening 51, of this evaporator, sealing of the end 78 of conduit 77 to the inlet opening 61 of the lower U-shaped sheet metal evaporator and the sealing of conduit 21 to the outlet opening 71 of this lower evaporator. By concentrating the first stages of expansion of the refrigerant to the Withdrawal of heat from the uppermost portion of chamber 12 in the vertically elongated home freezer refrigerator and thereafter cooling portions of the lower part of chamber 12 a more uniform temperature throughout the chamber from the top to the bottom thereof is obtained. In this manner the temperature gradient between the superimposed compartments of chamber 12 is reduced. When thermostatic bulb 24 has been reduced to a predetermined low temperature, preferably around 10 F., it influences switch 23 to cause the same to open the contacts 28 and 29 and thus break the electric circuit to the motor-compressor unit 16 to stop operation thereof.

While the embodiment of the present invention as herein disclosed constitutes a preferred! form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In a refrigerator, a cabinet having an outer housing, an open ended substantially U-shaped metallic liner with-- in and spaced from said housing forming the upright back and two opposed side walls only of a chamber in said cabinet, a unitary substantially U-shaped sheet metal evaporator wholly disposed within said liner, the bight portion ,.of said U-shaped evaporator intermediate arms ..thereof lying along one of said opposedside walls .of said ,tal wall of said chamber, the other ofsaid arms of said evaporator extending horizontally .across said chamber and dividing the interior thereof into an upper compartment and a lower compartment, said evaporator having refrigerant passages therein, means for supplying refrigerant to the passages in said evaporator, and said one arm of said evaporatorrand said pan member tying the legs of said U-shaped liner to one another against relative movement therebetween to provide a rigid box-like structure in said cabinet.

2. In a refrigerator, a cabinet having an outer housing, an open ended substantially U-shaped metallic liner spaced from said housing forming the back and opposed side walls only of a chamber within said cabinet, a unitary substantially U-shaped sheet metal evaporator wholly disposed within said liner, the bight portion of said U-shaped evaporator intermediate arms thereof lying along and being secured to one of the opposed side walls of said chamber, one of said arms of the evaporator being substantially flush with the upper edge of said liner and secured thereto for closing the upper open end thereof toprovide a top Wall of said chamber, a pan member separate from and secured to said liner at its lower edge for closing the lower open end thereof to provide a bottom wall of said chamber, said one arm of said evaporator and said pan member tying the legs of said U-shaped liner to one another against relative movement therebetween, insulating material in the space between said housing and said liner, the other of said arms of the evaporator .extending horizontally across said chamber and dividing same into an upper compartment and a lower compartment, said evaporator having refrigerant conveying passages formed in and traversing said arms and said bight portion thereof for cooling three walls of said upper compartment, means for supplying refrigerant to said passages and for withdrawing refrigerant therefrom, and said mean-s including a conduit portion extending along said liner in contact therewith at a fourth wall of said upper compartment intermediate the ends of the arms of said evaporator whereby to cool four walls thereof.

.3. In a refrigerator, .a cabinet havingan outerrhousing, ,an openrended substantially ,U-shaped metallic liner spaced from: said .housingrforming the back and opposed: side walls only of a chamber within said cabinet, .a unitary substantially U-shaped sheet metal evaporator wholly disposed within said liner, the bight portion of said U-shaped evaporator vintermediate arms thereof lying along and being secured to one of the opposed side walls of said chamber, one of said arms of the evaporator beingnsubstantially flush with the upper edge of said liner and .secured thereto for closing the upper open end thereof -to provide a top wall of said chamber, a pan member:separate from and secured to said liner at its lower edge for closing the lower-open end thereof toprovide a bottom wall of saidchamber, said one arm of said evaporator an said pan member tying the legs of said vU-shaped liner .to one another against relative movement therebetweeminsulating material in thespace between said housing-and said liner, the other of said arms of the evaporatorextending horizontally across said chamber and dividing same into an upper compartment and a lower compartment, said evaporator having refrigerant conveying passages formed in and traversing said arms and said bight portion thereof for cooling three Walls of said upper compartment, means for supplying refrigerant to portions of said evaporator in succession first through the passages in onearm thereof, then through the passages in said bight portion and thereafter through the passages in the other arm thereof and for withdrawing refrigerant therefrom to .cool three walls of said upper compartment, andsaid means including a fiat coiled conduit in said insulating space extending along said liner in contact with that pertionof a side wall of said chamber intermediate the ends of the arms of said evaporator whereby to 0001 four walls of said upper compartment.

References Cited in the file of this patent UNITED STATES PATENTS 2,290,190 Jacobs July 21, '1942 2,442,188 Bauman May 25, 1948 2,449,094 Wheeler Sept. '14, 1948 2,458,629 Orley Jan. 11, 1-949 2,509,011 Moore May 23, 1950 2,613,509 Phillip Oct. 14,1952 2,622,412 Staebler Dec. 23, "1952 

